package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.conditions.query.QueryChainWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.USER_FOLLOW_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key = USER_FOLLOW_KEY + userId;
        //判断是关注还是取关
        if(isFollow){
            //2.关注 新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            //用户为key 关注的用户为value存入Redis
            if(isSuccess){
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        }else {
            //3.取关 删除数据 mp
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserId));
            if(isSuccess){
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }

    /**
     * 判断是否关注
     * @param followUserId
     * @return
     */
    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("follow_user_id", followUserId).eq("user_id", userId).count();
        return Result.ok(count > 0);
    }

    /**
     * 共同关注
     * @param followUserId
     * @return
     */
    @Override
    public Result common(Long followUserId) {
        //获取当前用户id
        Long userId = UserHolder.getUser().getId();
        String key1 = USER_FOLLOW_KEY + userId;
        String key2 = USER_FOLLOW_KEY + followUserId;
        //获取共同关注的ids
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if (intersect == null || intersect.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        //将共同关注的id转换为Long
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //查询共同关注用户
        List<User> users = userService.listByIds(ids);
        //将共同关注用户转换为userDTO
        List<UserDTO> userDTOS = users.stream().map(user ->
                BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
